crypto: sun8i-ss - Fix memory leak of pad

It appears there are several failure return paths that don't seem
to be free'ing pad. Fix these.

Addresses-Coverity: ("Resource leak")
Fixes: d9b45418 ("crypto: sun8i-ss - support hash algorithms")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c

@@ -348,8 +348,10 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
 	bf = (__le32 *)pad;
 
 	result = kzalloc(digestsize, GFP_KERNEL | GFP_DMA);
-	if (!result)
+	if (!result) {
+		kfree(pad);
 		return -ENOMEM;
+	}
 
 	for (i = 0; i < MAX_SG; i++) {
 		rctx->t_dst[i].addr = 0;
@@ -436,10 +438,9 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
 		     DMA_TO_DEVICE);
 	dma_unmap_single(ss->dev, addr_res, digestsize, DMA_FROM_DEVICE);
 
-	kfree(pad);
-
 	memcpy(areq->result, result, algt->alg.hash.halg.digestsize);
 theend:
+	kfree(pad);
 	kfree(result);
 	crypto_finalize_hash_request(engine, breq, err);
 	return 0;